U.S. patent application number 14/159908 was filed with the patent office on 2014-05-15 for glide movement controller and power miter saw including such controller.
This patent application is currently assigned to Robert Bosch GmbH. The applicant listed for this patent is Robert Bosch GmbH, Robert Bosch Tool Corporation. Invention is credited to Jie Liu.
Application Number | 20140133900 14/159908 |
Document ID | / |
Family ID | 46640773 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140133900 |
Kind Code |
A1 |
Liu; Jie |
May 15, 2014 |
Glide Movement Controller and Power Miter Saw including such
Controller
Abstract
A glide movement controller for use with a hinge connection that
includes a shaft, as well as a hinge connection and a power saw
including such a controller. The glide movement controller includes
a generally U-shaped controller body configured to move towards the
shaft in a first direction such that resistance upon the shaft is
increased and away from the shaft in a second direction such that
resistance upon the shaft is decreased; a pair of apertures
extending through the controller body; and an interior bearing
surface defined on the controller body. The interior bearing
surface is configured and arranged to face the shaft. In certain
embodiments, at least a portion of the interior bearing surface is
located between the apertures.
Inventors: |
Liu; Jie; (Lisle,
IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Robert Bosch GmbH
Robert Bosch Tool Corporation |
Stuttgart
Broadview |
IL |
DE
US |
|
|
Assignee: |
Robert Bosch GmbH
Stuttgart
IL
Robert Bosch Tool Corporation
Broadview
|
Family ID: |
46640773 |
Appl. No.: |
14/159908 |
Filed: |
January 21, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13194670 |
Jul 29, 2011 |
8631734 |
|
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14159908 |
|
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Current U.S.
Class: |
403/120 |
Current CPC
Class: |
B27B 5/29 20130101; Y10T
16/05 20150115; F16C 11/103 20130101; Y10T 403/62 20150115; Y10T
16/537 20150115; Y10T 83/7697 20150401; Y10T 83/7693 20150401; Y10T
83/7788 20150401; B23D 47/00 20130101; Y10T 403/32614 20150115;
B23D 45/048 20130101; B23D 47/02 20130101; F16C 11/045 20130101;
B27B 5/208 20130101 |
Class at
Publication: |
403/120 |
International
Class: |
F16C 11/04 20060101
F16C011/04 |
Claims
1-17. (canceled)
18. A hinge connection between a first link and a second link, said
hinge connection comprising: a shaft that is fixed for rotation
with respect to said first link; a first bearing and a second
bearing associated with said second link, wherein said shaft is
seated within said first and second bearings; and a glide movement
controller operatively connected to the hinge connection, wherein
said glide movement controller comprises a controller body that is
configured and arranged to be moved such that resistance upon said
shaft is increased upon movement in a first direction and decreased
upon movement in a second direction, wherein said controller body
includes an interior bearing surface that is configured and
arranged to face said shaft, such that said interior bearing
surface provides the resistance for inhibiting, but not preventing,
rotation of said shaft, thereby inhibiting, but not preventing,
relative movement between said first and second links.
19. The hinge connection according to claim 18, further comprising:
a pair of apertures extending through said controller body, wherein
at least a portion of said interior bearing surface is located
between said apertures; a pair of threaded apertures formed in a
wall of said second link, whereby said threaded apertures of said
second link are aligned with said apertures of said controller
body; and a pair of threaded fasteners, whereby each of said
threaded fasteners is configured and arranged to extend through one
of said apertures of said controller body and to be secured into
one of said threaded apertures of said second link, wherein said
controller body is positioned between said first bearing and said
second bearing.
20. The hinge connection according to claim 19, wherein: said
controller body is generally U-shaped; and said interior bearing
surface includes a plurality of ribs extending in a direction
parallel to the shaft.
21. The hinge connection according to claim 20, further comprising:
a plurality of struts formed between adjacent pairs of said ribs,
wherein said struts extend transverse to said ribs; a plurality of
compartments defined between adjacent pairs of said ribs and
adjacent pairs of said struts; and a pair of curved interior
projections formed around each of said apertures of said controller
body.
22. The hinge connection according to claim 18, wherein said
interior bearing surface is configured and arranged to increase the
resistance by more tightly directly contacting said shaft and to
decrease the resistance by less tightly directly contacting said
shaft.
23. The hinge connection according to claim 18, wherein: said hinge
connection includes a spacer surrounding said shaft, whereby said
spacer is fixed for rotation with respect to said shaft; and said
interior bearing surface is configured and arranged to increase the
resistance by more tightly contacting said spacer and to decrease
the resistance by less tightly contacting said spacer.
Description
[0001] This patent is a Continuation-in-Part (CIP) application of
U.S. application Ser. No. 11/284,931, which was filed on Nov. 22,
2005.
BACKGROUND OF THE INVENTION
[0002] This patent generally relates to a glide movement controller
for use with power tools such as power miter and abrasive cut off
saws, and to saws including such a controller.
[0003] Miter saws have been the subject of continued research and
development efforts in the power tool arena for decades, and many
improvements have been made that has resulted in increased ease of
use and productivity. Artisans who install trim carpentry have used
power miter saws for some time and it is well known that wide stock
such as crown molding and the like often requires a miter saw with
either a bigger saw blade or a configuration that enables the blade
to be moved along a horizontal path away and toward the fence of
the miter saw. Such blade moving configurations are generally
marketed as sliding compound miter saws, principally because most
if not all commercially available saws of this type have a sliding
guide assembly comprised of elongated rods that slide in respective
bushings to move the saw blade and motor assembly relative to the
fence of the saw.
[0004] Such sliding guide assemblies are an expensive component of
such miter saws. The current state of the art for such sliding
miter saws includes a linear guide that typically consists of two
of such bushings and rod combinations. These relatively expensive
linear bearings consist of recirculating ball bearings that operate
together with turned, ground, polished and hardened steel rods that
are approximately 40 cm long and 30 mm in diameter. To have minimum
play and deflection of the saw blade and motor assembly, precise
fits are required between the rods and the linear recirculating
ball bearings over the entire linear travel of the rods. The rod
must be made of a high hardness steel to prevent indentation by the
hard steel balls. Such construction is relatively expensive.
[0005] Additionally, an undesirable feature of such bushing and rod
linear guides is that space must be provided behind the saw for the
rods to extend when the saw blade is positioned near the fence.
Because of this space requirement, such a sliding saw cannot be put
next to a wall which results in a larger footprint being occupied
by such a saw. Additionally, these bushings and rod linear guide
mechanisms are susceptible to damage from dirt and grit,
particularly if the saw is a sliding abrasive cut off saw where an
abrasive wheel is used to cut steel and other materials. The
abrasive wheel grinds its way through the steel and produces a
considerable volume of abrasive particles that generally come out
of the back of the saw. These abrasive particles can penetrate into
the ball bushings and damage the bearing. While it is possible to
cover the rods with a bellows or similar cover, the hostile
environment generally leads to degradation of the fabric and
penetration of the ball bushing by the abrasive particles.
[0006] There is a continuing need for improvement in the design and
development of miter and cut-off saws that have linear guide
assemblies.
SUMMARY OF THE INVENTION
[0007] A power miter saw including a saw base having a fence for
positioning a work piece, a table rotatably connected to the saw
base; a miter arm assembly for angularly positioning the table
relative to the saw base, a saw blade and motor assembly
operatively connected to the table, a linear guide mechanism
attached to the table and being configured to support the saw blade
and motor assembly and enable movement of the assembly along a
predetermined linear path in either forward or rearward directions,
the mechanism having a horizontal shaft about which the assembly is
pivotable to move a saw blade vertically into and out of cutting
position, the mechanism also having a multiple link hinge pivotally
interconnecting the motor assembly and the table with generally
horizontal shafts that are parallel to one another.
[0008] Also, A glide movement controller for use with a hinge
connection that includes a shaft, as well as a hinge connection and
a power saw including such a controller. The glide movement
controller includes a generally U-shaped controller body configured
to move towards the shaft in a first direction such that resistance
upon the shaft is increased and away from the shaft in a second
direction such that resistance upon the shaft is decreased; a pair
of apertures extending through the controller body; and an interior
bearing surface defined on the controller body. The interior
bearing surface is configured and arranged to face the shaft. In
certain embodiments, at least a portion of the interior bearing
surface is located between the apertures.
DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a right side perspective view of a first preferred
embodiment of the present invention, particularly illustrating the
saw blade being located in the extended position away from the
fence;
[0010] FIG. 2 is a right side perspective view of the embodiment
shown in FIG. 1, but illustrating the saw blade in a position near
the fence;
[0011] FIG. 3 is a side elevation of the embodiment shown in FIG. 1
with the saw blade in the extended position away from the
fence;
[0012] FIG. 4 is a rear view of the embodiment shown in FIG. 1,
with the saw blade away from the fence;
[0013] FIG. 5 is a right front perspective view of a second
preferred embodiment of the present invention, particularly
illustrating the saw blade being located in the extended position
away from the fence;
[0014] FIG. 6 is a right front perspective view of the embodiment
shown in FIG. 5, but illustrating the saw blade in a position near
the fence;
[0015] FIG. 7 is a side elevation of the embodiment shown in FIG. 5
but illustrating the saw blade in a position near the fence;
[0016] FIG. 8 is a rear view of the embodiment shown in FIG. 5,
with the saw blade in a position away from the fence;
[0017] FIG. 9 is a third preferred embodiment of the present
invention, particularly illustrating the saw blade being located in
the extended position away from the fence;
[0018] FIG. 10 is a side elevation of the embodiment shown in FIG.
9 with the saw blade in the extended position away from the
fence;
[0019] FIG. 11 is another side elevation of the embodiment shown in
FIG. 9, with the saw blade near the fence;
[0020] FIG. 12 is a rear view of the embodiment shown in FIG. 9,
with the saw blade located away the fence;
[0021] FIG. 13 is a perspective view of the right side of a miter
saw, with the blade and motor assembly in an extended and lowered
position, in accordance with another embodiment of the
invention;
[0022] FIG. 14 is a perspective view of the right side of the miter
saw shown in FIG. 13, with the blade and motor assembly in a
retracted and lowered position;
[0023] FIG. 15 is a perspective view of the left side of the miter
saw shown in FIG. 13, with the blade and motor assembly in an
extended position;
[0024] FIG. 16 is a perspective view of the left side of the miter
saw shown in FIG. 13, with the blade and motor assembly in the
retracted and lowered position;
[0025] FIG. 17 is a top plan view of the miter saw shown in FIG.
13, with the blade and motor assembly in the retracted and lowered
position and the blade being perpendicular to the fence;
[0026] FIG. 18 is a top plan view of the miter saw shown if FIG.
13, with the blade and motor assembly in the retracted and lowered
position and the blade being at a miter angle to the fence;
[0027] FIG. 19 is a perspective view of the left side of the miter
saw shown in FIG. 13, with the blade and motor assembly beveled to
the left side;
[0028] FIG. 20 is an enlarged perspective view of an embodiment of
a glide movement controller;
[0029] FIG. 21 is an exploded view of the glide movement controller
of FIG. 20;
[0030] FIG. 22 is a bottom perspective view of the glide movement
controller body;
[0031] FIG. 23 is a side cross-section of the glide movement
controller of FIG. 20, shows with an embodiment of a hinge
connection that includes an optional spacer; and
[0032] FIG. 24 is an end cross-section of the glide movement
controller and hinge connection of FIG. 23.
DETAILED DESCRIPTION
[0033] Various different embodiments of the glide movement
controller and miter saws are shown and described herein, with each
of the embodiments of the miter saws having a multiple hinge
linkage that is designated herein as a horizontal hinge linkage
that interconnects the saw blade and motor assembly to the table of
the miter saw. It should be understood that while it is referred to
herein as a generally horizontal hinge linkage, the several shafts
of the linkage may not always be exactly horizontal, and may have a
pivot axis that can vary up to about 30 degrees in either direction
from exact horizontal. However, it is preferred that the axes be in
a substantially horizontal orientation when the saw is set at a
zero degree bevel position. Regardless of the bevel angle or the
orientation of the surface on which the saw is supported, the
shafts are preferably substantially parallel to the arbor shaft in
which the blade is mounted and therefore substantially
perpendicular to the plane of the saw blade.
[0034] The horizontal hinge linkage is utilized rather than an
elongated rod and bushing configuration and provides increased
stiffness to undesired movement of the saw blade arising from
structural deflections during cutting operations. Some of the
embodiments also have a vertical hinge linkage for maintaining the
elevation of the saw pivot head (to which the saw blade and motor
assembly is attached) constant during movement of the saw blade and
motor assembly away and toward the fence during a cutting
operation. A third preferred embodiment utilizes the horizontal
hinge linkage together with a single rod and bushing arrangement
whereby the rod and bushing arrangement also maintains a constant
elevation of the saw pivot head as the saw blade and motor assembly
is moved toward and away from the fence during a cutting operation.
It should be understood that the saw blade and motor assembly is
pivotable about a saw pivot that is part of the saw pivot head,
which is attached to the horizontal hinge linkage. The saw blade
and motor assembly can be pivoted up out of contact with a work
piece or moved down into contact with a work piece during a cutting
operation as is conventional for miter saws.
[0035] Such hinge linkages have a cost advantage compared to
conventional bushing and rod guides because they have a simpler
construction, which may comprise as few as two generally planar
shaped linkages that are connected together by shafts that may
preferably incorporate rotary bushings or low cost ball bearings
and which are also linked to the support frame of the rotatable
table as well as to the saw pivot head. Tight tolerance fits
between hinge components are relatively easier to achieve using low
cost ball bearings that are preloaded in the axial direction so
that nearly all axial and radial play is removed. In contrast,
conventional bushings and sliding rod systems require expensive
manufacturing processes to ensure that the outside surface of the
rod is precise over its entire length. Another advantage of the use
of hinge linkages is that their stiffness characteristics are
determined primarily from the width of the hinge linkages as
measured along the pivot, i.e., shaft axis. Thus, increased system
stiffness can be achieved by making the hinge larger and this is
generally less expensive than using larger rods and bushings.
[0036] As previously mentioned, the horizontal hinge linkage pivots
around axes that are perpendicular to the cutting plane of the
blade and therefore provides increased stiffness along the axis of
rotation of the saw blade and because of this desirable
characteristic, the length of the hinge shafts is greater than
other shaft lengths such as those used in the vertical hinge
linkage. The structural stiffness is very important to the quality
of cuts made by the saw. Without the requisite structural
stiffness, it is common for the saw blade to deflect out of the
desired cutting plane on an intermittent basis which can result in
one or more cut discontinuities or jagged cut portions, rather than
a continuous smooth cut at the desired angle.
[0037] Another advantage of the hinge linkage is that it has
greatly reduced sensitivity to dirt and grit because the bearing
surfaces of a hinge linkage are not exposed but are contained
within a ball bearing or short rotary bushing Such ball bearing or
rotary bushings can be relatively easily sealed compared to a rod
and bushing system where the entire rod is a critical bearing
surface and therefore has to be sealed with a large accordion or
bellow shaped fabric or other type of cover which is often easily
damaged.
[0038] Turning now to the first preferred embodiment shown in FIGS.
1-4, the miter saw, indicated generally at 10, has a generally
circular base 12 with an attached fence 14, which base supports a
rotatable table 16 that has a miter arm control assembly, indicated
generally at 18, for adjusting the rotational position of the table
for setting the miter angle of work piece that would be placed on
the table 16. A saw blade and motor assembly, indicated generally
at 20, is operatively connected to the table 16 by a linear guide
mechanism, indicated generally at 22. The saw blade and motor
assembly 20 has an electric motor 24 that is operatively connected
through a belt and gear mechanism, not shown but located within
housing portion 26 that drives a saw blade 28. A handle 30 enables
an operator to move the blade and motor assembly 20 into and out of
engagement with a work piece that may be placed on the table 16
adjacent the fence 14. The blade and motor assembly 20 is pivotable
about a saw pivot shaft 32 that is connected to a saw pivot head 34
to which the linear guide mechanism 22 is attached. The blade and
motor assembly 20 is shown in FIG. 1 to be in a position where the
blade is moved to its extended position away from the fence 14 and
lowered into cutting position where a workpiece is placed on the
table 16. During operation, an operator places a work piece on the
table 16, brings the handle 30 down into cutting position either
before or after activating the motor 24 and then pushes the handle
30 toward the fence 14 to have the blade 28 cut the work piece. At
the end of the cut, the blade and motor assembly 20 would be
essentially in the position shown in FIG. 2 where the bottom reach
of the blade 28 is generally coextensive with the fence 14.
[0039] The linear guide mechanism 22 of the first preferred
embodiment shown in FIGS. 1-4 is designed so that the miter saw has
a dual bevel operation, rather than a single bevel operation,
meaning that the bevel angle can be adjusted either right or left
from the normal zero angle or position wherein the plane of the
blade 28 is perpendicular to the plane of the top surface of the
table 16. The blade and motor assembly 20 as well as the linear
guide mechanism and rotate about a bevel pivot shaft 36, with the
linear guide mechanism having a support frame 38 with a generally
cylindrical end portion 40 to which the bevel pivot shaft 36 is
connected to. The shaft 36 extends through an opening in an
enlarged extension 42 of the table 16. Thus, the end portion 40 can
rotate relative to the extension 42 and be supported by the shaft
36. The support frame 38 is preferably a casting that has a lower
flange 44, an upper flange 46 as well as vertically oriented
flanges 48 and 50.
[0040] A horizontal hinge linkage is comprised of links 52 and 54
which have adjacent ends connected together by a shaft 56. The saw
pivot head 34 has a pair of spaced flanges 58 as well as a single
flange 60 located below the flanges 58. The link 54 has its
opposite end connected to the flanges 58 by a shaft 62. Similarly,
the opposite end of the link 52 is connected to the vertical
flanges 48 and 50 by a shaft 64. As previously mentioned and while
not specifically illustrated, the shafts 32, 62, 56, 64, 78 and 82
are preferably of the type which utilize rotary bushings or low
cost ball bearings so that they are freely rotatable and will have
an extended useful life.
[0041] As is best shown in FIGS. 1 and 2, the link 52 has a
generally L-shaped side configuration with the transverse extension
66 having the aperture in which the shaft 56 is located. This
permits the two links 52 and 54 to be folded together in a
generally parallel arrangement as shown in FIG. 2 when the blade
and motor assembly 20 is moved into its final cutting position
where the blade is adjacent to the fence 14. As is best shown in
FIG. 4, the width of the links 52 and 54 is relatively large and
therefore the shafts 56, 62 and 64 that interconnect the links 52
and 54 with one another and with the saw pivot head 34 and support
frame 38 are relatively long. This contributes to the desirable
stiffness of the linear guide mechanism which substantially
reduces, if not eliminates, any movement by the blade out of the
cutting plane which can result in poor quality cutting. Stated in
other words, the extremely wide links and their coupling to the saw
pivot head and support frame 38 results in high rigidity reducing
torsional and linear deflection of the saw blade away from its
intended cutting plane which is very desirable from a cut quality
standpoint.
[0042] As best shown in FIG. 4, the link 52 is not a solid
construction, but has side walls 68 and end walls 70 with cross
braces 72 provided to provide increased overall strength for the
link. The link 54 is similarly constructed as is shown in FIG. 1,
it also having similarly configured side walls, end walls and cross
braces. The hinge links 52 and 54 are preferably die cast aluminum
but can be steel stamping if desired.
[0043] The vertical hinge linkage is located below the horizontal
hinge linkage and it comprises links 74 and 76 which have adjacent
ends connected together by a vertical shaft 78. The links 74 and 76
are not as wide as the horizontal hinge links 52 and 54 for the
reason that their functionality is to maintain the elevation of the
saw pivot head 34 constant during movement of the blade and motor
assembly 20 toward and away from the fence 14. Elevational
deflections are not as critical for a miter saw cut quality for the
reason that the work piece is generally being completely cut
through.
[0044] The narrower links 74 and 76 are vertically displaced from
one another which requires the elongated vertical shaft 78 to
extend to interconnect them. The link 74 is located between the
horizontal flanges 44 and 46 and is pivotally connected to these
flanges by a shaft 80. Similarly, the link 76 has spaced flange
portions that are connected to the flange 60 by a shaft 82. As is
shown in FIG. 1, the flange 60 is located beneath the near flange
58 and the flanges 44 and 46 are also located beneath the vertical
flanges 48 and 50, and the shaft 78 that interconnects the links 74
and 76 extends away or to the left side of the saw (as viewed from
the handle 30) so that when the vertical and horizontal linkages
are folded together as shown in FIG. 2, little if any portion of
the links extend outside of the width of the flanges 48 and 50.
This is significant in that changing of the bevel angle of the
blade and motor assembly 20 can be accomplished in either the left
or right direction and the hinge linkages will not interfere with
the dual bevel adjusting capability.
[0045] It should also be apparent from FIG. 2 that when the blade
and motor assembly 20 are moved as far toward the fence 14 as is
possible, the linkages do not extend in any rearward direction
beyond the original position end of the support frame 38. This
enables the miter saw to be placed near a wall, for example, and be
fully operational, unlike many conventional sliding rod and bushing
configurations of compound miter saws.
[0046] A second preferred embodiment is shown in FIGS. 5-8 and have
many similar components as the embodiment shown in FIGS. 1-4. In
the following description, components that are labeled with the
same numbers as those shown and described with regard to the first
preferred embodiment are substantially similar in their design,
configuration and operation and therefore will not be described in
detail. Components with reference numbers having a prime or double
prime designation are similar to those that are identified with
regard to the embodiment shown in FIGS. 1-4, but may have some
structural differences which are apparent or which will be
generally described, or which will be given different numbers than
those illustrated in FIGS. 1-4.
[0047] The second preferred embodiment is indicated generally at
100 in FIGS. 5-8 and has many similarities to the first preferred
embodiment, but while the first embodiment is a dual bevel
configuration saw, the second embodiment saw 100 is a single bevel
configuration. The links 74' and 76' are connected together by a
shaft 78' that is not as long as the shaft 78 of the first
preferred embodiment, because the links 74' and 76' are vertically
adjacent one another rather than being spaced apart. Also, the link
76' is at an elevation that is substantially similar to the
elevation of the link 54' and therefore unable to fold toward the
link 52'' and 54'. Thus, the connection between link 74' and 76'
extends outwardly away from the links 52' and 54'. Because of the
outward extension, particularly when it is folded as shown in FIGS.
6 and 8, the links interfere with other portions of the saw 100
when the saw would be pivoted in the counterclockwise direction as
shown in FIG. 8. Therefore, the single bevel operation of this
second preferred embodiment is in the clockwise direction as shown
in FIG. 8.
[0048] A third preferred embodiment of the invention is the saw 110
that is shown in FIGS. 9-12 is less detail than the embodiments of
FIGS. 1-8. Saw 110 has a horizontal hinge linkage comprising links
52'' and 54'' that are interconnected and operate substantially
similar to those described in the embodiments of FIGS. 1-8. The saw
pivot head 34'' has a slightly different configuration and the end
of the link 54'' is connected to the saw pivot shaft 32 which is
also journaled in the saw pivot head 34''. An elongated rod 112 is
journaled in a bushing (not shown but located in the upper end of
support frame 38) and maintains the saw pivot head 34'' at a
constant elevation as the blade and motor assembly 22 moves the
blade 28 toward the fence 14. Only one rod 112 is provided for the
reason that control of the saw blade cutting plane is provided by
the horizontal hinge linkage, as is the case with the other
embodiments shown in FIGS. 1-8, and the only function that is
performed by the rod 112 is to keep the pivot head 34'' at a
constant elevation during operation. In this regard, the blade and
motor assembly 20 is shown in its retracted position in FIGS. 9 and
10 and in the cutting position in FIG. 11 where the blade 28 is
adjacent the fence 14. In the position shown in FIG. 11, it is
apparent that the rod 112 will extend beyond the rear surface of
the support frame 38'' which requires a larger footprint in that it
would not be possible to place the saw 110 with the support frame
38'' located close to a wall or other similar surface. Thus, while
this embodiment does not have the space advantages of the first and
second preferred embodiments, this embodiment has the advantage of
controlling the saw blade cutting plane by a generally horizontal
hinge as is achieved in all embodiments and only one rod and
bushing combination is required which provides a cost benefit
compared to conventional arrangements which have a pair of rod and
bushing configurations.
[0049] Another described embodiment of the miter saw is shown in
FIGS. 13-19 and is indicated generally at 200. This embodiment is
also described in related U.S. application Ser. No. ______ (GBC
Docket No. 0212.072978C2), which is hereby incorporated by
reference it its entirety. Many of the components are similar to
the first embodiment 10 so that where reference numbers are the
same as the description of the FIG. 1, such components and their
functionality are very similar, if not identical. Components with
reference numbers above 200 are sufficiently different from
analogous components of the other embodiments to warrant separate
numbers or are new in the fourth preferred embodiment.
[0050] Turning to FIGS. 13 and 14, the miter saw 200 also has a
generally circular base 12 with an attached fence 14. The base 12
supports a rotatable table 16 that has a miter arm control
assembly, indicated generally at 18, for adjusting the rotational
position of the table for setting the miter angle of a workpiece
that would be placed on the table. A saw blade and motor assembly,
indicated generally at 20, is operatively connected to the table 16
by a linear guide mechanism, indicated generally at 202. The saw
blade and motor assembly 20 has an electric motor 24 that is
operably connected through a belt and gear mechanism(not shown),
but located within the housing portion 26 that drives a saw blade
28. A handle 30 enables the operator to move the blade and motor
assembly 20 into and out of engagement with a workpiece (not shown)
that is placed on the table 16 adjacent the fence 14.
[0051] The blade and motor assembly 20 is pivotable about a saw
pivot connection shaft 204 extending between a pair of spaced outer
flanges 206 on a pivot head 208. When the handle 30 is lowered by
an operator, the blade 28 will be lowered into its cutting position
and slightly penetrates a slot 210 formed in the table 16. The
pivot head 208 also has a pair of spaced inner flanges 212 (best
shown in FIG. 13) that extend in the opposite direction from the
outer flanges 206 that are connected to the blade and motor
assembly 20, and offset from the center of the pivot head 208,
opposite one of the outer flanges 206. The inner flanges 212 are
provided between a pair of spaced outer flanges 218 extending from
one end of a first horizontal link 214. A pivot connection shaft
216 extends horizontally through holes in the inner and outer
flanges 212 and 218 to pivotally connect the inner and the outer
flanges 212, 218. Together the inner flanges 212 of the pivot head
208, the pivot connection shaft 216 and the outer flanges 218 of
the first horizontal link 214 form a horizontal hinge connection
220.
[0052] At the opposite end from the horizontal hinge connection
220, the first horizontal link 214 is connected to a slightly
longer second horizontal link 222 by another horizontal hinge
connection 224. It should be understood, however, that the miter
saw 200 may include one or more additional horizontal links that
may be connected to the first and second links 214, 222 without
departing from the scope of the patent. Included in the hinge
connection 224 is a pair of spaced inner flanges 226 that extend
from the end of the first horizontal link 214 opposite the end
having outer flanges 218. The inner flanges 226 are provided
between and pivotally connected to a pair of spaced outer flanges
228 extending from the upper end portion of the second horizontal
link 222, by a pivot connection shaft 230.
[0053] The second horizontal link 222 has its lower end portion
connected to a vertical support 232 by a horizontal hinge
connection 234. The hinge connection 234 includes a pair of spaced
outer flanges 236 (best shown in FIG. 15) extending from the top of
the vertical support 232 and a pair of inner flanges (not shown)
extending from the lower end of the horizontal link 222 and
provided between the outer flanges of the vertical support. A pivot
connection shaft 238 extends through the outer flanges 236 of the
vertical support 232 and the inner flanges of the second horizontal
link 222 for a pivotal connection. The outer flanges 228 of the
second horizontal link 222 in the hinge connection 224 extends at
an angle of approximately 30 degrees from the generally linear
longitudinal portion of the second horizontal link to enable the
first horizontal link 214 to be folded close to the second
horizontal link, as shown in FIG. 14. It is to be understood that
the angle other than the described above may be utilized as
well.
[0054] As is best shown in FIGS. 14 and 16, when the blade and
motor assembly 20 is in its retracted position, the second
horizontal link 222 is in a generally vertical orientation. It
should be appreciated that the horizontal pivot connection shafts
216, 230, 238, and the corresponding hinge connections 220, 224,
234, are oriented parallel to one another and substantially
perpendicular to the plane of the blade 28. The first and second
horizontal links 214, 222 are relatively wide, approximately 80 to
160 millimeters and the thickness of them is substantial,
approximately 10 to 80 millimeters so that they resist bending
which would detrimentally affect the quality of the cut by the
blade 28. The length of the first horizontal link 214 is
approximately 3/4 of the length of the second horizontal link 222.
In one embodiment, the length of the first horizontal link 214 is
approximately 120 to 220 millimeters and that of the second
horizontal link 222 is approximately 200 to 300 millimeters so that
the point of the blade 28 that make contact with the workpiece is
at a sufficient distance from the fence 14 to cut the intended
workpiece, but before the contact point reaches the end of the slot
210 provided in the table 210. Of course, it should be understood
that the width, the thickness, and the length of the first and
second links 214, 222 other than those described above may be
utilized as well.
[0055] The vertical support 232 is integrally formed with a support
frame 240 that is generally cylindrically shaped. Of course, the
support frame 240 may take the form of various shapes and have a
number of different sizes. A bevel pivot shaft 242 supported by an
extension 244 of the table 16 enables the support frame 240 and the
vertical support 232 to pivot either to the left or right of the
plane of the blade 28 for the purpose of providing bevel cuts. The
vertical support 232 also has a side mounting structure 246 with a
pivot block 248 for pivotally supporting an angled first vertical
link 250, which has a pair of outer flanges 252 at one end. The
pivot block 248 is provided between and connected to the two outer
flanges 252 of the first vertical link 250 by a vertical pivot
connection shaft 254 that extends through the holes formed in the
outer flanges and the pivot block. The outer flanges 252, the pivot
block 248 and the pivot connection shaft 254 combine to form a
vertical hinge connection 256. It should be noted that the pivot
block 248 can be an integral part of the vertical support 232, or
it can be a separate component that is affixed to the vertical
support 232.
[0056] Referring to FIGS. 13, 15 and 16, the first vertical link
250 has a pair of spaced inner flanges 258 extending from the end
opposite the end having the outer flanges 252. The inner flanges
258 are provided between a pair of spaced outer flanges 260
extending from a second vertical link 262. A vertical pivot
connection shaft 264 extends through the aligned holes in the inner
and outer flanges 258, 260 to pivotally connect the first and
second vertical links 250, 260 together and form a vertical hinge
connection 266. While the inner flanges 258 are described as being
"spaced," it should be understood that they are not necessarily
separated. They can also be integrally connected by a somewhat
narrower piece provided between the flanges 258. Alternatively, the
inner flanges 258 can also be replaced with one cylindrical piece
protruding from the end of the link 250. As best shown in FIG. 15,
the outer and the inner flanges 260, 258 of the second vertical
link 262 and the first vertical link 250 extend at a slight angle
from the linear portion of each of the first and second vertical
links 250,262 to enable the first and second vertical links 250,
262 to be folded close to each other, as shown in FIG. 16.
Preferably, the flanges 258, 260 should extend at an angle of
approximately 30 to 120 degrees relative to the linear portion of
the respective first and second vertical links. It is to be
understood that the angle other than the described above may be
utilized as well.
[0057] At the opposite end from the outer flanges 260, a pair of
spaced outer flanges 268 extend from the second vertical link 262
and are pivotally connected to a pivot block 270 provided between
the two outer flanges by a vertically oriented pivot connection
shaft 272 (best shown in FIGS. 13 and 14), thereby forming another
vertical hinge connection 274. The pivot block 270 is attached to
the pivot head 208 on the opposite side from the outer flanges 206
and adjacent the inner flanges 212 of the pivot head.
[0058] As with the embodiment shown in FIG. 13, the vertical pivot
connection shafts 254, 264, 272 maintain the elevation of the pivot
head 206 substantially constant relative to the table 16. The
length of the first vertical link 250 is approximately the same as
the length of the second vertical link 262, and each of the first
and second vertical links 250, 262 are approximately 7/10 of the
length of the second horizontal link 222. In one embodiment, the
length of the first vertical link 250 is approximately 120 to 220
millimeters and that of the second vertical link 262 is also
approximately 120 to 220 millimeters. The width and thickness of
the first and second vertical links 250, 262 are comparable to the
first and second horizontal links 214, 222. However, the amount of
possible bending of the vertical links 250, 262 is not as critical
as bending that could occur with the horizontal links 214, 222
inasmuch as the quality of a cut is generally not affected by
vertical movement of the blade during extension and retraction
because the blade penetrates the slot 210 during most cutting
operations. Of course, it is to be understood that the width, the
thickness, and the length of the first and second links 214, 222
other than those described above may be utilized as well. As is
evident from the drawings, the horizontal and vertical links 214,
222, 250, 262 are not solid but may be constructed from cast of
aluminum and have reinforcing ribs 276 (best shown in FIG. 14) that
extend across the interior of the links to impart additional
strength. In some embodiments, the horizontal and vertical links
214, 222, 250, 262 may be constructed from steel stamping, sheet
metal, or any high strength plastic.
[0059] Additional structural strength is provided with the fourth
embodiment for the reason that all the horizontal and the vertical
hinge connections 220 224, 234, 256, 266, 274 have outer flanges
that fit outside a pair of inner flanges or pivot blocks, which
support each the horizontal and vertical links 214, 222, 250, 262
at both ends rather than an overhung load connection. The
double-ended support provides a stronger connection that imparts an
increased strength to the links. The horizontal and vertical pivot
connection shafts 216, 230, 238, 254, 264, 272 are, therefore, also
supported at opposite ends, which is a stronger connection.
[0060] In the described fourth embodiment, the vertical hinge
connection 256 at the lower end of the first vertical link 250 is
provided at the top portion of the vertical support 232 (not
including the outer flanges 236) and is slightly below the vertical
hinge connection 266 at the other end of the vertical link 250
(best shown in FIG. 14). Accordingly, the vertical link 250 extends
at an angle between the vertical hinge connections 256 and 266. It
should be understood, however, that the length of the vertical
support 232 may be increased so that the location of the pivot
block 248, and accordingly, the vertical hinge connection 256, may
be at the same height as the vertical hinge connection 266. In
other words, the first vertical link 250 may extend substantially
parallel to the table top 16 as is the second vertical link 262.
However, with this arrangement, there may be an issue of the miter
saw 200 being undesirably top heavy.
[0061] Another consideration is that the angle between the first
and second horizontal links 214, 222 as determined by the line of
action between a line extending through pivot connection shafts 230
and 216 in the horizontal hinge connections 224 and 220 relative to
the line of action through pivot connection shafts 230 and 238 in
the horizontal hinge connections 224 and 234, identified as angle
.theta..sub.1 in FIG. 15 should be less than 130.degree. when the
saw is fully extended to prevent a toggle action of the links.
While not shown, the angle between the first and second vertical
links 250 and 262 as determined by the line of action between a
line extending through vertically oriented pivot connection shafts
264 and 254 in the vertical hinge connections 266 and 256 relative
to the line of action through vertical pivot connection shafts 264
and 272 in the vertical hinge connections 266 and 274, also should
be less than 130.degree. when the saw is fully extended to prevent
a toggle action of the links. The toggle action is defined herein
to mean an increased necessary force to push the blade and motor
assembly 20 from its extended position, shown in FIGS. 13 and 15
toward the retracted position shown in FIGS. 14 and 16. If a toggle
action is experienced, a greater noticeable and appreciable force
is required to start the movement. If the angles of the links are
less than 130.degree., such toggle action is not experienced.
[0062] During operation, an operator places a workpiece on the
table 16, brings the handle 30 down into cutting position either
before or after activating the motor 24, as shown in FIGS. 13 and
15, and then pushes the handle 30 toward the fence 14 to have the
blade 28 cut the workpiece. At the end of the cut, the blade and
motor assembly 20 would be essentially in the position shown in
FIGS. 14 and 16, where the bottom reach of the blade 28 is
generally coextensive with the fence 14.
[0063] As is shown in FIGS. 15 and 16, the first and second
vertical links 250, 262 are located beneath the first and second
horizontal links 214, 222 and the vertical connection hinge 266
that interconnects the vertical links extends away or to the left
side of the saw (as viewed from the handle 30). In this manner,
when the saw 200 is in a retracted position and the vertical and
horizontal links 214, 222, 250, 262 are folded together, as shown
in FIGS. 16-19, only a small portion (e.g., approximately 20 to 100
millimeters) of the vertical links 250, 262 extend outside of the
width of the horizontal links 214, 222. This is significant in that
changing of the bevel angle of the blade and motor assembly 20 can
be accomplished in either the left or right direction and the
vertical links 250, 262 will not interfere with the dual bevel
adjusting capability, as illustrated in FIG. 19.
[0064] Another desirable attribute of this described embodiment is
particularly illustrated in FIGS. 14, 16 and 17 wherein the blade
and motor assembly 20 is in its retracted position and the second
horizontal link 214 is substantially vertical. Since the link 214
does not extend rearwardly beyond the vertical support 232, it can
be appreciated that the saw 200 can be placed very close to a rear
wall or the like without impairing the normal operation of the
saw.
[0065] Optionally, one or more of the hinge connections in any of
the embodiments, such as hinge connection 224 of the embodiment
shown in FIGS. 13-19, includes a glide movement controller 310,
which is shown in detail in FIGS. 20-24. The glide movement
controller 310 is used for controlling the smoothness of the saw's
glide action. In the various embodiments of the linear guide
mechanism described above, the gliding action of the blade and
motor assembly 20 with respect to the table 16 is very smooth, and
thus only minimal pressure upon the handle 30 is required for
moving assembly 20. Accordingly, there may be certain situations
where the user desires more force to be required to accomplish such
gliding movement, so that the saw does not move more easily than
desired. Thus, as explained next, the glide movement controller 310
creates some resistance to such gliding movement of the linear
glide mechanism.
[0066] As can be seen in FIGS. 20-24, this embodiment of the glide
movement controller 310 includes a controller body 312 and a pair
of fastening members, such as screws 314. The controller body 312
is preferably generally U-shaped, when viewed from the side, as can
be seen in FIG. 21. Of course other shapes are also contemplated,
as long as the necessary frictional resistance to rotation of shaft
230 can be provided and the shape of the controller body does not
block the relative movement of the horizontal links 214 and 222
with respect to each other.
[0067] As best seen in FIGS. 21 and 22, the glide controller body
312 includes an interior bearing surface 316 that is configured to
make contact with shaft 230, or with a component that is fixed for
rotation with the shaft. In the described embodiment, the interior
bearing surface includes three ribs 317A, 317B, and 317C. Although
three ribs are preferred, a greater or lesser number of ribs may
also be used, depending upon the situation. Additionally, it is
also contemplated that ribs may be eliminated in favor of a solid
bearing surface.
[0068] As shown in FIG. 22, in order to provide additional support
for ribs 317A-317C, a plurality of smaller support struts 319 may
optionally be provided to extend between adjacent ribs in the
direction transverse to the ribs 317A-317C. In the embodiment
shown, the struts 319 are shorter than the ribs 317, and thus do
not constitute part of the interior bearing surface 316.
[0069] Preferably, some form of lubricant is applied to the area of
the interior bearing surface 316 to reduce wear. If the ribs
317A-317C and struts 319 are provided, the lubricant, which is
preferably of a gel-like consistency, can be retained within the
compartments formed by the ribs and struts.
[0070] For receiving the screws 314, the glide controller body 312
includes a pair of apertures 318 that extend through the body 312.
Apertures 318 are both preferably slightly oblong to allow for a
little play. Additionally, in order to provide additional strength
to the areas near the apertures 318, a pair of curved interior
projections 328A and 328B are preferably provided around each of
the apertures 318.
[0071] Turning now to FIGS. 23 and 24, one example of an embodiment
of a hinge connection that can be used with the glide movement
controller 310 will be described. Of course, other designs of hinge
connections could also cooperate with the present glide movement
controller. Some example of other designs of hinge connections are
described in related U.S. application Ser. No. ______ (GBC Docket
No. 0212.072978C1), which is hereby incorporated by reference it
its entirety.
[0072] The embodiment of the hinge connection shown in FIGS. 23 and
24 includes an optional spacer 330 surrounding the shaft 230 (which
spacer is not shown in most of the other figures). This spacer 330
is fixed for rotation with the shaft 230, so when the interior
bearing surface 316 of the controller body 312 contacts the
optional spacer 330, the frictional resistance applied to the
spacer 330 is transferred to the shaft 230. Of course, if the
optional spacer is not included, the frictional force of the
interior bearing surface 316 of the controller body 312 is applied
directly to the shaft 230.
[0073] In this embodiment of the hinge connection, one end of the
shaft 230 includes a threaded aperture 404 for receiving a threaded
member such as screw 406, while the other end includes a hex socket
408 for receiving a hex wrench to apply a rotary force to (or to
prevent rotation of) the shaft 230 during tightening of the screw
406. As known in the art, the hex socket 408 could be replaced with
any known configuration for receiving a tool for preventing
rotation or for applying a rotary force to the shaft. This end of
the shaft 230 also preferably includes a first shoulder portion 407
that is configured to bear against the transverse surface of
enlarged bore 409, and a second shoulder portion 428 that is
configured to bear against bearing 410.
[0074] The shaft 230 is rotatably held within two sets of bearings
410 and 412, which are seated within recesses 414, 416,
respectively, in inner flanges 226. Bearings 410 and 412 may be of
any desired type, such as ball bearings, needle bearings, roller
bearings, journal bearings, etc. The optional spacer 330, if
provided, surrounds the shaft 230 in a location between the bearing
410 and the bearing 412. Finally, a bushing 420 is provided to
surround the axial end of the shaft 230 in the area between the
bearing 412 and head 422 of the screw 406. As can be seen in FIG.
23, the bushing 420 preferably includes a bushing flange 424 for
receiving the axial force from the screw head 422 as the screw 406
is tightened. Upon tightening of the screw 406, the spacer 330 (if
provided) will be fixed for rotation with the shaft 230, as
mentioned above.
[0075] Returning to FIG. 21, a wall 320 can be seen on horizontal
link 214 between inner flanges 226. The wall 320 includes a pair of
threaded apertures 322 (only one of which is visible in FIG. 21).
To attach the glide controller body 312 to the hinge 224, one screw
314 is inserted into each aperture 318, and then into each threaded
aperture 322 within wall 320. Tightening of the screws 314 causes
the interior bearing surface 316 of the body 312 to more tightly
contact the shaft 230, thereby applying resistance to the relative
movement of the links 214, 222 of the hinge 224, resulting in
resistance to the gliding movement of the entire linear glide
mechanism. Of course, loosening of the screws 314 diminishes the
amount of resistance.
[0076] In the embodiment of the glide movement controller 310 shown
in FIGS. 20-24, the apertures 318 in controller body 312 each
preferably include a counterbore 324 (FIGS. 20 and 21) so that the
heads of the screws 314 can be seated below the outer peripheral
surface 326 of the controller body 312. Such a configuration
eliminates possible interference between the screw heads and the
adjacent surfaces of link 222, which interference could otherwise
prevent the full movement of links 214 and 222 with respect to each
other. As can be seen in FIGS. 20 and 21, the shape of the outer
peripheral surface 326 of controller body 312 matches the shape of
the corresponding surfaces of the adjacent inner flanges 226,
thereby eliminating the possibility of interference with adjacent
surfaces of link 222, as well as providing a smooth appearance for
the glide movement controller 310.
[0077] The glide movement controller 310 has been described in
connection with a miter saw. However, it is contemplated that such
a controller could be used with other devices, such as other power
tools, and especially with other devices that include linear guide
mechanisms of the types described herein.
[0078] While various embodiments of the invention have been shown
and described, it should be understood that other modifications,
substitutions and alternatives are apparent to one of ordinary
skill in the art. Such modifications, substitutions and
alternatives can be made without departing from the spirit and
scope of the invention, which should be determined from the
appended claims.
[0079] Various features of the invention are set forth in the
following claims.
* * * * *